DRM can be used to collect user information secretly, undetectably and unethically. It can coerce people to buy certain specific hardware or software. It can be, and is, used to limit usage of software products by the very people who paid for them. Often in order to use DRM'd software the user is forced to 'register' the product possibly --probably-- subjecting himself or herself to advertising and spam, or worse. In conjunction with current copyright law DRM undermines the future public domain. It inconveniences common everyday users unduly, making them jump through hoops that savvy pirates simply ignore. And the bottom line: As for decreasing piracy, DRM doesn't even work.